BACKGROUND: Posttraumatic Stress Disorder constitutes a substantial proportion of the burden of illness among veterans. However, current PTSD treatments are not effective for all, and a significant number remain symptomatic despite pharmacotherapy and psychotherapy. As a result, there has been increased interest within the military and VA in Complementary and Alternative Medicine approaches, such as yoga, to improve symptoms without requiring direct verbal processing of the trauma. Yoga provides an innovative approach to calming hyperarousal, reducing numbness/avoidance, and improving self-regulation of emotions, while cultivating physical and emotional well-being. Because of this unique approach to the biological, psychological, and social dimensions of PTSD, we believe that yoga interventions are poised to meet the demand for more effective PTSD treatment options for veterans. Recent research indicates that yoga interventions can be delivered successfully to individuals who have PTSD and have potential to reduce clinician rated and self-reported overall PTSD symptoms, depression and anxiety. However, few studies exist that have evaluated yoga for PTSD and they have involved small sample sizes and are either uncontrolled or waitlist/usual care controlled. Also, there is much variation among studies in the style and components of yoga interventions. Thus, a randomized controlled trial of a standardized, traditional, holistic yoga intervention is urgently needed to inform VA policy makers and clinicians of the potential benefits of yoga as an adjunct to currently available PTSD treatments. OBJECTIVE: The overall goal of this project is to compare the effects of a 16-week Holistic Yoga Program (HYP) with a 16-week Wellness Lifestyle Program (WLP) on PTSD and related symptoms and outcomes. This project has three specific aims: 1) to compare the effects of the interventions (HYP vs. WLP) on overall PTSD symptom severity; 2) compare the interventions' effects on PTSD-specific symptoms (anger, sleep), PTSD-related symptoms (depression, anxiety, pain) and related outcomes (well-being/quality of life); 3) to manualize the Holistic Yoga Program and training process for experienced yoga teachers to deliver HYP to individuals who have PTSD in order to facilitate future study and dissemination efforts. METHODS: Our study sample will include 232 outpatients with a clinician-confirmed diagnosis of PTSD, recruited from the Roudebush VA Medical Center as well as metropolitan area mental health clinics/clinicians and military/veterans' organizations, who will be randomly assigned to receive the Holistic Yoga Program (HYP) or the Wellness Lifestyle Program (WLP). The HYP will involve a standardized 16-week intervention consisting of: 1) in-person group yoga class taught by a yoga instructor registered through the Yoga Alliance at least at the 200 hour level; 2) classes will include yoga postures, breathing practices, deep muscle contraction practices, relaxation practices, and teacher-led discussions to exchange lessons learned, and introduce relevant aspects of yoga philosophy; 3) guided yoga postures, breath and relaxation practice audio recordings for home-use; and 4) a Participant Handbook to reinforce concepts taught during in-person sessions. The WLP is an attention control comprised of low intensity physical activity and didactics about wellness topics that will also encourage home practice and provide a Participant Handbook to reinforce concepts taught during in- person sessions.